Fix documentation for no-return-argument-annotation-in-stub [PYI050] (#7708)

## Summary

The markdown documentation was present, but in the wrong place, so was
not displaying on the website. I moved it and added some references.

Related to #2646.

## Test Plan

`python scripts/check_docs_formatted.py`

crates/ruff_linter/src/rules/flake8_pyi/rules/no_return_argument_annotation.rs

@@ -8,11 +8,6 @@ use ruff_text_size::Ranged;
 use crate::checkers::ast::Checker;
 use crate::settings::types::PythonVersion::Py311;
 
-#[violation]
-pub struct NoReturnArgumentAnnotationInStub {
-    module: TypingModule,
-}
-
 /// ## What it does
 /// Checks for uses of `typing.NoReturn` (and `typing_extensions.NoReturn`) in
 /// stubs.
@@ -37,6 +32,15 @@ pub struct NoReturnArgumentAnnotationInStub {
 ///
 /// def foo(x: Never): ...
 /// ```
+///
+/// ## References
+/// - [Python documentation: `typing.Never`](https://docs.python.org/3/library/typing.html#typing.Never)
+/// - [Python documentation: `typing.NoReturn`](https://docs.python.org/3/library/typing.html#typing.NoReturn)
+#[violation]
+pub struct NoReturnArgumentAnnotationInStub {
+    module: TypingModule,
+}
+
 impl Violation for NoReturnArgumentAnnotationInStub {
     #[derive_message_formats]
     fn message(&self) -> String {

scripts/check_docs_formatted.py

@@ -55,6 +55,7 @@ KNOWN_FORMATTING_VIOLATIONS = [
     "multiple-statements-on-one-line-semicolon",
     "no-blank-line-before-function",
     "no-indented-block-comment",
+    "no-return-argument-annotation-in-stub",
     "no-space-after-block-comment",
     "no-space-after-inline-comment",
     "non-empty-stub-body",